U.S. Pat. No. 5,495,239 discloses a method where a measurement information relay apparatus is set on a distribution transformer of an electrical power system network and the apparatus transfers communication between a meter apparatus of generating measurement information and a server apparatus of collecting the measurement information. Also, U.S. Pat. No. 5,691,715 discloses a method of registering in advance a device identifier of a meter apparatus in a measurement information relay apparatus and a server apparatus in a fixed manner to thereby block measurement information from an unauthorized meter apparatus. Further, U.S. Pat. No. 6,115,676 discloses a method of giving a relay block instruction for an overlimit household meter apparatus.
In recent years, according to NIST (National Institute of Standards and Technology) and CENELEC (European Committee for Electrotechnical Standardization), a system for solving a problem in electrical power transmission between suppliers and consumers by using information techniques in a positive manner is named “smart grid” and standardization activities of various kinds of techniques are promoted. Among these, an application called “HEMS (Home Energy Management System)” is assumed to control a household electrical appliance in a consumer's home based on the electrical power supply-and-demand trends.
The HEMS can be provided in an embedded manner as a function of a home meter apparatus, or in a separated manner from the meter apparatus as another energy management apparatus (HEMS apparatus), where the connection method to the Internet is various. Especially, in the latter case, there is a problem that it is difficult to correctly form a pair of a meter apparatus and an energy management apparatus installed in a customer's home, by a server apparatus on the Internet, wherein the server apparatus manages measurement information collection and supply-and-demand control. In this case, it is not possible to collect an actual electrical power usage state of the customer's home as measurement information from the meter apparatus and instruct an energy management apparatus to perform electrical control of household electrical appliances, wherein the energy management apparatus is separately installed from the meter apparatus in the customer's home.
By combining U.S. Pat. Nos. 5,495,239, 5,691,715 and 6,115,676 in a simple manner, it is possible collect measurement information from a normal meter apparatus and give a relay block instruction for a meter apparatus in a case where a specific condition is satisfied. However, as described above, in a system in which the meter apparatus and the energy management apparatus are separately installed in a home, there is a problem that it is difficult to dynamically associate the meter apparatus and the energy management apparatus in the same household by the server apparatus side on the Internet. Also, in a case where the registration information of each apparatus including a corresponding device identifier is transmitted or received in a plaintext form via the Internet, there is a security problem that it is not possible to secure the confidentiality and integrity of communication messages.
The embodiment aims to provide an energy management apparatus and an energy management system which correctly forms a pair of a meter apparatus and an energy management apparatus installed in a customer's home by a server apparatus.